This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 24 |
| 5 | 71 |
| 6 | 224 |
| 7 | 710 |
| 8 | 2318 |
| 9 | 7659 |
| 10 | 25703 |
| 11 | 87153 |
| 12 | 298574 |
| 13 | 1031104 |
| 14 | 3587263 |
| 15 | 12558652 |
| 16 | 44214807 |
| 17 | 156438309 |
| 18 | 555973965 |
| 19 | 1983817178 |
| 20 | 7104313970 |
| 21 | 25525304569 |
| 22 | 91986529421 |
| 23 | 332408847422 |
| 24 | 1204259931815 |
| 25 | 4373027942634 |
| 26 | 15914143511582 |
| 27 | 58030451159889 |